Tyneside Society of Model & Experimental Engineers
November 2019 – News Letter
Preamble
I’d planned to have something out in October, a respectable three months on from the previous issue, but life has an irritating habit of getting in the way of things. As Edmund Blackadder so eloquently put it – “The path of my life is strewn with cowpats from the Devil’s own Satanic herd”. Be assured, however, that I’ve swept up and what follows is wholly fragrant ….
Around and About the Club
Big things
have been happening out on the grass of late as work has progressed steadily with
building the new Carriage Shed for the raised-track riding trucks. Many cubic
metres of soil have been excavated to prepare the ground for the floor-slab (6m
long by 2m wide by 10cm deep) which sits several centimetres below the
surrounding ground level. Four courses of blockwork are raised on this to
roof-eaves level. A door-frame and sill have been fabricated in steel which
occupy the full width of the track-ward end. Provision is made in the floor to
bring in mains electricity.
Whilst the
ground works for the carriage shed were underway, the area in front of the
locomotive shed was also prepared to accommodate the new dual-gauge traverser
and the slab for this was poured at the same time.
Work also
continues with improvements to the track signalling and point control systems.
Receiving attention now are the points between the station loop and main line
so that these cannot be operated whilst a train is in transit. Additional
train-detectors have been installed in the track and associated cables laid-in
back to the Signal Box where a new cabinet houses the extra circuitry required.
Creosote Day,
Saturday 7th September, witnessed a good turnout of willing helpers
to get this annual maintenance job done. Both ground-level and raised tracks
were thoroughly treated using a combination of spray-guns and brushes.
If you’ve
visited the TSMEE website recently, you’ll have noticed a quite radical change
in appearance and content. John Rowley has taken over the job of webmaster and
is keen to stress that it is, presently, very much “work in progress”. User
feedback and constructive comments are welcomed.
Events …
Open Weekend 27/28th
July
This annual
two-day event was not blessed with particularly good weather. It rained
on-and-off on the Saturday and Sunday was dry but overcast. Nevertheless, there
was a respectable turnout of both TSMEE members and visitors, the latter hailing
from as far afield as Scotland, Cumbria, York and Leeds.
Visiting
locomotives were :– in 3-1/2” gauge BR
“Britannia” 4-6-2, Great Central O4 2-8-0, Freelance 4-8-2 – in 5” gauge “Chub” 0-4-0 Tank, BR Standard 4 2-6-4 Tank,
NER Q6 0-8-0, NER B2 4-6-0 – and in 7-1/4” gauge GWR 14XX 0-4-2 Tank .
Saturday lunch
was Fish ‘n Chips and on Sunday our Catering Stalwarts laid on their usual
splendid buffet.
Trip
down the Tyne 31st August 2019
Six
members joined our party on the “Fortuna” for a cruise down to Tynemouth from
the Quayside in Newcastle. The weather was reasonable, even allowing for the
blustery wind, and we all enjoyed the trip.
There is a full and very informative commentary on the way to Tynemouth. I have made the trip a couple of times over the years and I am amazed by the way that Tyneside industrial heritage has disappeared in a comparatively short time. It used to be the remains of ship yards, dry docks and associated industries all the way to Tynemouth. Now much of the bank-side is wooded and under modern housing. It all looks very different.
The remaining working areas are impressive and Tyne Dock is massive. The Fish Quay and Tynemouth with the Harbour Lights, like much else of the riverside, are becoming tourist attractions. That’s progress, so we all went to the bar and drank to the past. Malcolm Phillips
Trip
to see the G5 at Shildon and the P2 under construction at Darlington, 7th October 2019.
Another
enjoyable day out, perhaps more related to model engineering. Volunteers at
both sites were very helpful and thanks are due to Phil Work who kindly
arranged tea and biscuits at Shildon.
The
G5 is not quite an engine yet, but most of the parts are ready to go together.
The frames, boiler, cab and plate-work just need finishing touches. The bogie
for the 0-4-4 and one set of driving wheels have been finished but the crank
axle has yet to arrive, as manufacture of parts and machining is all done
outside. The group has been working to original plans and has had to make many
patterns, some of which are placed beside the finished castings.
From
Shildon we proceeded to Darlington. The P2, to be named “Prince of Wales”, is a
truly impressive machine. Like the G5 it has yet to go onto its wheels, all of
which have had their tyres polished to a mirror finish. Cab and smokebox are on the frames and the
boiler cladding is set up on frames beside the locomotive as the boiler is yet
to come from Meiningen.
We were told about some of the technical problems – the wheel flanges have been computer designed to ease passage round curves on Heritage Railways and steam distribution will be by poppet valves.
The original Gresley design was not too successful so the designers have used the designs evolved in America after the war which were better. Boiler design has been modified by experience with Tornado and their boilers are interchangeable.
I
do not know what will become of the polished wheels – one of the volunteers
told me that the painters were upset because on its first trip to York of thirty
miles, their beautiful paint finish was spoiled by excess grease and oil coming
out of the axle boxes!
The
NELPG shops were closed so we completed the trip with a visit to the Head of
Steam Museum across the way from the Hopetown works. This is a nice museum with
exhibits of Stockton and Darlington and NER origin. Hackworth’s “Derwent” and
“Locomotion” are well displayed and there are some interesting small exhibits. Malcolm
Phillips
For your diary …
Public Running
Day – Santa Special – Sunday 1st December
Christmas Tea
– Sunday 22nd December
Something a bit different now – Gordon
Bullard has very kindly submitted the following rather interesting article…
An Automatic
Cylinder Drain-cock
Back in the 1980’s over a pie and a pint in a local hostelry, a friend and I were discussing the pros and cons of cylinder drain cocks and associated linkage to the cab of a miniature steam locomotive.
The locomotive he was building had two sets of Stephenson’s valve gear and an axle pump between the frames, together with lubricator linkage which left little room for direct drain- cock rodding. We discussed the possibility of automatic drain cocks and I suggested that a small inverted safety valve type of arrangement might be possible.
A set of small valves was made and fitted, each consisting of a stainless ball which was held on its seat by a small bronze spring. The valves performed well but they looked like upside-down safety valves, which is, of course, exactly what they were.
Clearly, a horizontal arrangement was required which would be more prototypical of full sized practice. So, another set of valves was made in a tee configuration with basically the same internal arrangement but in a horizontal orientation.
These valves worked reasonably well. They certainly cleared the cylinder condensate very efficiently but for some reason when the locomotive was running slight puffs of steam were occasionally noticeable.
Closer observation showed that one of the valves seemed to be working well with no visible leakage whilst the loco was running. With the expectation that the poor sealing of the three sub standard valves was probable due to poor workmanship on my part, all of the valves were disassembled for examination.
I was amazed to find that I had forgotten to put a
spring in the valve that worked perfectly.
The valves were quickly reassembled without springs and found to all
work perfectly. Since then I have fitted
this type of valve onto three of my locomotives with no failures. The last loco was to LBSC’s “Maisie” design
and has run on the club track on numerous occasions. The attached drawing shows the design of the
valve which is made of bar material with a silver-soldered joint.
It took a while to work out how the valve worked without a spring. When the locomotive is stationary any condensation in the cylinder drains down into the valve where the ball is resting on the bottom of the chamber so any water can drain away via the front hole.
When the regulator is opened a combination of condensate and steam enters the valve where the ball is unable to seat properly due to the turbulence in the chamber. A combination of water and steam exits the valve due to this turbulence until all of the water is displaced, which leaves the chamber full of steam which in turn forces the ball onto its seat. It’s as simple as that.
You may well ask what the reduced diameter on the rear
of the valve is for. It is purely there
to improve the fitting visually, disguising the fact that it is just a piece of
simple bar material. For members who
follow full size practice and require drain piping to the locomotive’s buffer
beam, the front of the valve seat could
have a small ME thread machined onto it to take a nut, nipple and associated
pipe.
In conclusion, this simple valve is easy to produce, is fully automatic in operation and requires no linkage to the cab. It would be easy to say that I had a light bulb type of moment concerning this valve’s conception but in reality it came about more by accident than design.
Drain-cocks fitted to 3-1/2″ “Maisie”
Postamble
As I remarked in the previous issue, a
Newsletter requires News, and this one would have been a rather thin affair but
for the contributions of Malcolm Phillips and Gordon Bullard. My thanks to them
both.
Membership Subscriptions will be due for renewal at the end of the year. The cost remains at £35 Single and £45 Family. Our Treasurer Ian Spencer will take payment in cash or cheques (payable to “TSMEE Ltd”).
In order to fix the cylinders all work requiring them to be mounted on the machines need to be done. The cylinder and valve chest covers had been drilled and tapped for the cover studs, just leaving the main steam pipe flange studs drilling and tapping. I then realized the hole for the relief valves in the back covers had not been made for the K3. The H4 did not need them . So the rotary table was once again set up with each cylinder on its vertical centreline so the hole could be drilled and tapped. Here the dial gauge is being used to accurately align the cylinder back plate so the hole can be located.
Here the hole has been drilled and the tap is in the collet to accurately form the screw thread.
Looking at the frames and the position of the cylinder fixing bolts it was realized that a number of the bolt holes should have been countersunk on the inside as the bolt heads would be fouled by the components they were holding on. I looked at ways of doing this operation, hoping my Dremel with it's right angle drive would do the trick, but it is just too long with the frame plates just over 4 inches apart. It was impossible to countersink the from inside the frames. I decided to make a front driven countersink and the photo shows the silver steel device after turning.
The countersink is in the rotary table to mill the cutting teeth.
After being hardened and tempered the countersink is held in a portable drilling machine and pulled towards the operator to create the 45 degree chamfer in the hole.
As the bolts are made, rather than change tools to part them off, I found it quicker to saw them off. Each one was then driven into the previously reamed hole to check the length and fit. Once a section was done the bolts were carefully removed and the head machined to the correct diameter and thickness before being finally driven home and tightened up.
A view of bolts temporarily fitted.
Another view of the bolts at the back of a cylinder
My working notes for the bolts showing the various types, sizes and numbers required. In all in the two locomotives the cylinder and frame bolts add up to a total of nearly 600 bolts made in S303 stainless steel.
A view here of the backplate for one of the sandboxes on the inverted K3. These were machined in pairs and the fixing holes drilled and used as a template for drilling the frames from the outside.
All the frame stretchers were originally fitted using mild steel bolts and each was removed and refitted using stainless steel fitted bolts to ensure their security. These are the stretchers in front of the firebox on the K3
With the sandbox backplate temporarily fitted inside the frame and the four fixings studs inserted for the brake hanger bracket it can be seen there id little room for error in the location of the frame brackets and motion brackets.
Here the backplate for the K3 gravity sandbox is tried in place between the inside cylinder and leading hornblock
The K3 buffer beam had originally been attached with mild steel hex head bolts. Here it has been removed and all the bolt holes have been countersunk to receive the correct slightly domed countersunk head bolts.
The buffer beam after refitting with the right type of fixing
The backplate for the K3 gravity sander machined to size.
The first stage in building the sand boxes. These are mad using 1/8" brass plate and are silver soldered together. The capacity of the box is not important but the extra weight of the thicker plate will be useful. Whilst the sanders will be working it is unlikely they will ever be needed so the reduced volume is acceptable
Here the underside of the sandbox can be seen in situ
The leading sandboxes almost finished looking from above.
The boxes for the steam sanders ready to receive the filler pipes
A sandbox from below. The outlet hole is yet to be made.
The sandbox filler pipes are elliptical in cross section. Hear the brass bar is in the milling machine using the rotary table to step machine the ellipse.
The machining data drawing for the ellipse.
A filler pipe in place. A round pipe through the frame will go to the filling point on the footplate.
K3 front sandbox ready for cleaning up and painting
All four K3 sandboxes
K3 Pony truck after first coat of finish paint
K3 pony truck wheel set after painting
K3 pony truck bottom bolster painted
2-1 gear stretcher and swing link pony truck stretcher after changing fixing bolts. Will be painter with inside of frames.
Outside of frames after replacing bolts
Bracket at back of frame is pivot point for damper operating lever in cab
Completed pony wheel splasher
Test fitting of pony wheel splasher before cleaning up soldered joints
Drain cock cross shaft frame bearings at front of cylinders
Support bracket for dummy oil separator for exhaust injector
The H4 and K3 axlebox oil trays are topped up through filler points in the front of the tray. This is the first operation in making the oil fillers for both locomotives
Here the first of the bushes for the filler and drain points are located
Now cut into handed pairs they are prepared for machining the spigots that will be inserted into the oil trays
Setting up in the four jaw chuck
First spigot drilled and turned
Four fillers ready for fitting
Under tray with filler fitted and fluxed for soldering
Soldering done
Four axleboxes with the fillers installed
K3 driving axle masked up ready for primer
K3 driving and coupled wheel sets after priming
K3 driving and coupled wheel sets with first coat of gloss black
K3 frames following painting with primer
K3 frames following gloss black
K3 buffer beams painted red. Red paint is known for its transparency and two or three more coats were needed to get a satisfactory colour density.
The majority of the frame inside is painted black, with the centre section red. To help with coverage the frame stays , horn blocks and brackets were given a couple of coats by brush, and the rest was spray painted.
The red section after painting.
K3 crank axle painted red
Another view of the red painted section and the now painted sand boxes
Hornstays all painted
With the frames painted and ready for all the attachments, the cylinders became the next parts to be mounted. The inside cylinder is not attached directly to the frames, being bolted to the outside cylinders, which in turn are fixed to the frames. This means the three cylinders need to be bolted together before the assembly is bolted into the frame openings. I noted the main steam pipe flanges had not been drilled for the studs , so a drilling jig was made and used to complete this job with the cylinder mounted on an angle plate in the drilling machine.
A view from above of the inside cylinder which rests in openings in the frames, theoretically positioned accurately so the massive block of the cylinders maintains the alignment of the frame structure.
Full size practice was to make these joints face to face, the only sealing being to coat the surfaces with boiled linseed oil. This presumably was satisfactory, aided no doubt by the joint being subject to exhaust steam pressure only. In the case of the model, a belt and braces system was adopted, the faces being carefully machined, and polished on a surface plate using fine wet and dry papers. The joint was made using heat resistant paper and anti seize grease.
Here the right hand cylinder is attached to the inside.
A view of the underside of the cylinders showing the position of the hexagon nuts. The three plugs on the inside cylinder close the openings into the cavity around the cylinder that has been filled with RTV to provide some measure of insulation.
The cylinder assembly from the back
The cylinder assembly from the back
The cylinder assembly from underneath
The cylinder assembly from the front
The cylinder assembly now inserted in the frames and bolted up
The inside cylinder cladding needs to be fitted now, and here is insulation placed in the cavity under the cylinder
The thin sheet cladding bolted in position.
Generally the K3 and the H4 have been progressed equally, but the painting and erection of the K3 frames and cylinders have left the H4 quite a long way behind. The rest of the progress photographs for 2018 are of the H4 going through the processes described for the K3. These highlight the differences between the two and add some of the operations that were omitted from the K3 descriptions. Here the front buffer beam has been removed so the backing angle at the bottom edge can be fitted and the countersunk bolts flushed off.
H4 front buffers finish painted
Buffer beam painted flatted off and lined ready for transfer letters and numbers
The support bracket for the oil trap is a different design to that on the K3
The cylinder assembly after priming
H4 frames after priming. Previously painted stretchers masked up
Wheel sets primed and ready for rubbing down and gloss paint
Small parts assembled and prepared for primer.
Leaf springs, horn stays, inside cylinder cladding and oil trap bracket primed one side
Gloss paint to crank webs.
Leaf springs, horn stays, sand boxes, cylinder cladding being glossed
The H4 buffer beam now back in place and the transfer lettering applied. The transfers are by one of the commercial suppliers, but comparisons with photographs of the prototype show the font used is not bold enough. Finding replacements has been impossible and the story of making them will be told later
After carefully rubbing down and masking the outside of the frames are ready for gloss
The first coat of gloss didn't go well and it all had to be rubbed back almost to the primer, but the second coat went well with the spray gun settings properly adjusted for the prevailing conditions in December
The final direct attachments to the frames are the footplate support angles. Fitted at the front and back of the frame only they are curved to both inside and external radii and present a challenge in forming to keep them straight in plan. Those in just behind the front buffer beam are too tight a radius to bend up from angle so they were machined out of brass plate and silver soldered to their adjacent straight angle continuation pieces. Here the plate is being bored in the lathe
The outside is now turned to form the angle section
The angle rings were cut into four pieces and silver soldered to the straight sections of angle needed for the front sections, four for the H4 as the curved angle is required both inside and outside the frame, and two for the K3 which has none inside the frame.
Showing the right hand side angles being fitted to the H4
The sections at the rear of the frame are fixed under the cab and extend forward to the rear footplate support bracket. Conveniently the smokebox is about the right radius for these angles so the bending could be done with the assistance of smokebox.
The frame end drawing was printed full size and used to check the shape of the bent up angle.
A drilling jig was made up from a piece of scrap bar and used to check the holes previously drilled in the frames before being used to drill the angles.
Once all the angles were made they were primed ready to be fitted.
The angle fitted to the rear of the H4
And to the front end of the H4. This of course is the first part of the footplate angle manufacture, the outside edge of the footplate also needs angles at a later stage in the construction. I just need to be sure they are done before the smokeboxes are finally fitted. This completes this Stage of the construction as we are now at the end of 2018. The next instalment sees the painting and lining of the H4 frames and wheels, the manufacture of the main crossheads, piston rods and pistons and the beginning of the machining of the con rods and coupling rods.
